Virgin Money has announced a push into small business banking as the firm looks to narrow the gap with Britain’s biggest lenders.

The challenger bank said it would launch an SME savings account in January 2018 as a first step towards offering more products to business customers.

The FTSE 250 firm has set its sights on securing £5 billion of SME deposits within five years in a bid to capitalise on what it describes as an “attractive, but poorly served market”.

However, shares fell more than 4% in morning trading after the company warned that its annual share of gross lending would be at the lower end of its 3% to 3.5% forecast.

The bank said the change was driven by a need to manage margin amid pressures in the mortgage market.

Virgin Money also pencilled in banking net interest margin to drop from 170 basis points to 165 basis points in 2018, but said it was still on track to meet its full-year financial targets.

Chief executive Jayne-Anne Gadhia said: “We are also delighted to announce the start of our journey into SME banking and we will be launching a new SME savings account in January 2018.

“This will enable us to start developing relationships with business customers and lay the foundations for potential broader future development in this attractive, but poorly served market.

“We start the next phase of our evolution from a very strong position.”

Alongside the business banking drive, the firm said it would roll out a new digital banking platform in 2019.

Ms Gadhia added: “Traditional banks are investing in digital transformation but are burdened by legacy systems; whilst digital start-ups currently lack the customer base to disrupt the sector on any significant scale.

“Our end-to-end platform will enable us to capture market share by taking full advantage of our unique position and competitive advantages which are defined by a well-known and trusted brand, no legacy issues and an established scalable customer base.”